mode7: update a fast screen clear routine

asm_routines/gr_hlin.s

@@ -2,53 +2,6 @@
 ;= ROUTINES
 ;=====================================================================
 
-
-clear_screens:
-	;===================================
-	; Clear top/bottom of page 0
-	;===================================
-
-	lda     #$0
-	sta     DRAW_PAGE
-	jsr     clear_top
-	jsr     clear_bottom
-
-	;===================================
-	; Clear top/bottom of page 1
-	;===================================
-
-	lda     #$4
-	sta     DRAW_PAGE
-	jsr     clear_top
-	jsr     clear_bottom
-
-	rts
-
-
-clear_screens_notext:
-	;===================================
-	; Clear top/bottom of page 0
-	;===================================
-
-	lda     #$0
-	sta     DRAW_PAGE
-	jsr     clear_top
-	lda	#$0
-	jsr     clear_bottom_a
-
-	;===================================
-	; Clear top/bottom of page 1
-	;===================================
-
-	lda     #$4
-	sta     DRAW_PAGE
-	jsr     clear_top
-	lda	#$0
-	jsr     clear_bottom_a
-
-	rts
-
-
 	;================================
 	; hlin_setup
 	;================================
@@ -168,69 +121,3 @@ hlin_single_bottom_loop:
 	rts
 
 
-	;=============================
-	; clear_top
-	;=============================
-clear_top:
-	lda	#$00
-
-	;=============================
-	; clear_top_a
-	;=============================
-clear_top_a:
-
-	sta	COLOR
-
-	; HLIN Y, V2 AT A
-
-	lda	#39
-	sta	V2
-
-	lda	#0
-
-clear_top_loop:
-	ldy	#0
-	pha
-
-	jsr	hlin_double
-
-	pla
-	clc
-	adc	#$2
-	cmp	#40
-	bne	clear_top_loop
-
-	rts
-
-	;=============================
-	; clear_bottom
-	;=============================
-clear_bottom:
-	lda	#$a0	; NORMAL space
-
-clear_bottom_a:
-
-	sta	COLOR
-
-	lda	#40
-	sta	V2
-
-clear_bottom_loop:
-	ldy	#0
-	pha
-
-	jsr	hlin_double
-
-	pla
-	clc
-	adc	#$2
-	cmp	#48
-	bne	clear_bottom_loop
-
-	rts
-
-	; move these to zero page for slight speed increase?
-gr_offsets:
-	.word	$400,$480,$500,$580,$600,$680,$700,$780
-	.word	$428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8
-	.word	$450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0

asm_routines/gr_offsets.s

@@ -0,0 +1,5 @@
+	; move these to zero page for slight speed increase?
+gr_offsets:
+	.word	$400,$480,$500,$580,$600,$680,$700,$780
+	.word	$428,$4a8,$528,$5a8,$628,$6a8,$728,$7a8
+	.word	$450,$4d0,$550,$5d0,$650,$6d0,$750,$7d0

asm_routines/gr_slow_clear.s

@@ -0,0 +1,115 @@
+;=====================================================================
+;= ROUTINES
+;=====================================================================
+
+
+clear_screens:
+	;===================================
+	; Clear top/bottom of page 0
+	;===================================
+
+	lda     #$0
+	sta     DRAW_PAGE
+	jsr     clear_top
+	jsr     clear_bottom
+
+	;===================================
+	; Clear top/bottom of page 1
+	;===================================
+
+	lda     #$4
+	sta     DRAW_PAGE
+	jsr     clear_top
+	jsr     clear_bottom
+
+	rts
+
+
+clear_screens_notext:
+	;===================================
+	; Clear top/bottom of page 0
+	;===================================
+
+	lda     #$0
+	sta     DRAW_PAGE
+	jsr     clear_top
+	lda	#$0
+	jsr     clear_bottom_a
+
+	;===================================
+	; Clear top/bottom of page 1
+	;===================================
+
+	lda     #$4
+	sta     DRAW_PAGE
+	jsr     clear_top
+	lda	#$0
+	jsr     clear_bottom_a
+
+	rts
+
+
+
+	;=============================
+	; clear_top
+	;=============================
+	; takes 2+10+	(24+703 )*20	+6
+	; 14,558 cycles(?) 15ms, 70Hz
+clear_top:
+	lda	#$00							; 2
+
+	;=============================
+	; clear_top_a
+	;=============================
+clear_top_a:
+
+	sta	COLOR							; 3
+
+	; HLIN Y, V2 AT A
+
+	lda	#39							; 2
+	sta	V2							; 3
+
+	lda	#0							; 2
+
+clear_top_loop:
+	ldy	#0							; 2
+	pha								; 3
+
+	jsr	hlin_double						; 6+
+
+	pla								; 4
+	clc								; 2
+	adc	#$2							; 2
+	cmp	#40							; 2
+	bne	clear_top_loop						; 2nt/3
+
+	rts								; 6
+
+	;=============================
+	; clear_bottom
+	;=============================
+clear_bottom:
+	lda	#$a0	; NORMAL space
+
+clear_bottom_a:
+
+	sta	COLOR
+
+	lda	#40
+	sta	V2
+
+clear_bottom_loop:
+	ldy	#0
+	pha
+
+	jsr	hlin_double
+
+	pla
+	clc
+	adc	#$2
+	cmp	#48
+	bne	clear_bottom_loop
+
+	rts
+

mode7/Makefile

@@ -27,8 +27,9 @@ MODE7_ISLAND:	mode7_island.o
 
 mode7_island.o:	mode7.s island_lookup.s island_map.inc \
 	zp.inc sprites.inc \
+	../asm_routines/gr_hlin.s \
 	../asm_routines/multiply_fast.s \
-	../asm_routines/hlin_clearscreen.s \
+	../asm_routines/gr_fast_clear.s \
 	../asm_routines/pageflip.s \
 	../asm_routines/gr_setpage.s \
 	../asm_routines/keypress.s \
@@ -41,8 +42,9 @@ MODE7_CHECKERBOARD:	mode7_checkerboard.o
 
 mode7_checkerboard.o:	mode7.s checkerboard_lookup.s \
 	zp.inc sprites.inc \
+	../asm_routines/gr_hlin.s \
 	../asm_routines/multiply_fast.s \
-	../asm_routines/hlin_clearscreen.s \
+	../asm_routines/gr_fast_clear.s \
 	../asm_routines/pageflip.s \
 	../asm_routines/gr_setpage.s \
 	../asm_routines/keypress.s \
@@ -58,7 +60,8 @@ MODE7_RAINBOW:	mode7_rainbow.o
 mode7_rainbow.o:	mode7.s rainbow_lookup.s \
 	zp.inc sprites.inc \
 	../asm_routines/multiply_fast.s \
-	../asm_routines/hlin_clearscreen.s \
+	../asm_routines/gr_fast_clear.s \
+	../asm_routines/gr_hlin.s \
 	../asm_routines/pageflip.s \
 	../asm_routines/gr_setpage.s \
 	../asm_routines/keypress.s \
@@ -71,7 +74,8 @@ SCROLL_DEMO:	scroll_demo.o
 
 scroll_demo.o:	scroll_demo.s \
 	deater_scroll.inc \
-	../asm_routines/hlin_clearscreen.s \
+	../asm_routines/gr_hlin.s \
+	../asm_routines/gr_fast_clear.s \
 	../asm_routines/gr_scroll.s \
 	../asm_routines/pageflip.s \
 	../asm_routines/gr_setpage.s
@@ -82,7 +86,8 @@ SKY_DEMO:	sky_demo.o
 
 sky_demo.o:	sky_demo.s \
 	starry_sky.scroll \
-	../asm_routines/hlin_clearscreen.s \
+	../asm_routines/gr_hlin.s \
+	../asm_routines/gr_fast_clear.s \
 	../asm_routines/gr_scroll.s \
 	../asm_routines/pageflip.s \
 	../asm_routines/gr_setpage.s
@@ -92,10 +97,10 @@ STARFIELD_DEMO:	starfield_demo.o
 	ld65 -o STARFIELD_DEMO starfield_demo.o -C ./apple2_1000.inc
 
 starfield_demo.o:	starfield_demo.s \
-	../asm_routines/hlin_clearscreen.s \
 	../asm_routines/gr_scroll.s \
 	../asm_routines/pageflip.s \
-	../asm_routines/gr_setpage.s
+	../asm_routines/gr_setpage.s \
+	../asm_routines/gr_fast_clear.s
 	ca65 -o starfield_demo.o starfield_demo.s -l starfield_demo.lst
 
 scroller:	scroller.o

mode7/mode7.s

@@ -1114,12 +1114,14 @@ exit:
 ; External modules
 ;===============================================
 
-.include "../asm_routines/hlin_clearscreen.s"
+.include "../asm_routines/gr_hlin.s"
 .include "../asm_routines/pageflip.s"
 .include "../asm_routines/gr_setpage.s"
 .include "../asm_routines/keypress.s"
 .include "../asm_routines/gr_putsprite.s"
 .include "../asm_routines/text_print.s"
+.include "../asm_routines/gr_offsets.s"
+.include "../asm_routines/gr_fast_clear.s"
 
 .if .def(CHECKERBOARD_MAP)
 .include "../asm_routines/gr_scroll.s"

mode7/scroll_demo.s

@@ -36,10 +36,11 @@ scroll_forever:
 ;===============================================
 ; Routines
 ;===============================================
-.include "../asm_routines/hlin_clearscreen.s"
+.include "../asm_routines/gr_fast_clear.s"
 .include "../asm_routines/gr_scroll.s"
 .include "../asm_routines/pageflip.s"
 .include "../asm_routines/gr_setpage.s"
+.include "../asm_routines/gr_offsets.s"
 
 ;===============================================
 ; Variables

mode7/sky_demo.s

@@ -51,12 +51,13 @@ scroll_forever:
 ;===============================================
 ; Routines
 ;===============================================
-.include "../asm_routines/hlin_clearscreen.s"
+.include "../asm_routines/gr_fast_clear.s"
 .include "../asm_routines/gr_scroll.s"
 .include "../asm_routines/pageflip.s"
 .include "../asm_routines/gr_setpage.s"
 .include "../asm_routines/keypress.s"
 .include "../asm_routines/bg_scroll.s"
+.include "../asm_routines/gr_offsets.s"
 
 ;===============================================
 ; Variables

mode7/starfield_demo.s

@@ -25,15 +25,15 @@ NUMSTARS	EQU	16
 	;===============
 	; Init Variables
 	;===============
-	lda	#0
+	lda	#0							; 2
-	sta	DRAW_PAGE
+	sta	DRAW_PAGE						; 3
-	sta	RANDOM_POINTER
+	sta	RANDOM_POINTER						; 3
 
-	ldy	#(NUMSTARS-1)
+	ldy	#(NUMSTARS-1)						; 2
 init_stars:
-	jsr	random_star
+	jsr	random_star						; 6
-	dey
+	dey								; 2
-	bpl	init_stars
+	bpl	init_stars						; 2nt/3
 
 	;===========================
 	;===========================
@@ -46,8 +46,8 @@ starfield_loop:
 	;===============
 	; clear screen
 	;===============
-	jsr	clear_top
+	jsr	clear_top						; 6+
-
+									; 6047
 	;===============
 	; draw stars
 	;===============
@@ -312,12 +312,14 @@ random_star:
 ; External modules
 ;===============================================
 
-.include "../asm_routines/hlin_clearscreen.s"
+;.include "../asm_routines/hlin_clearscreen.s"
 .include "../asm_routines/pageflip.s"
 .include "../asm_routines/gr_setpage.s"
 .include "../asm_routines/keypress.s"
 .include "../asm_routines/gr_putsprite.s"
 .include "../asm_routines/text_print.s"
+.include "../asm_routines/gr_offsets.s"
+.include "../asm_routines/gr_fast_clear.s"
 
 ;===============================================
 ; Variables